The display setting application has trouble to manage a dual-head monitor setup. When trying to select the external one, it often freeze and become unresponsive. I didn't had this kind of issue with the same monitor and my previous laptop. I'm using an intel video card, and randr extension seems to work perfectly.

I tried to strace the process to look for contention point without much success. All I could find was this repeated attempt to read on an unindentified file descriptor:
3187  sendmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"l\1\1\1\34\0\0\0\25\0\0\0}\0\0\0\10\1g\0\1s\0\0\1\1o\0\25\0\0\0"..., 172}], msg_controllen=0, msg_flags=0}, MSG_NOSIGNAL) = 172
3187  poll([{fd=5, events=POLLIN}, {fd=4, events=POLLIN}, {fd=6, events=POLLIN}], 3, 4294967295) = 1 ([{fd=4, revents=POLLIN}])
3187  read(5, 0x7f1cc2282bd0, 16)       = -1 EAGAIN (Resource temporarily unavailable)

Reproducible: 

Steps to Reproduce: